The Course Instructor of the course FIN 3203 wants to know whether his student can adequately describe the role of corporate tax on estimating WACC. In such a situation he has provided the following information: The capital structure of the company is found to be 30 percent debt; 10 percent preferred stock and 60 percent common stock. The cost of financing with preferred stock is 9 percent; the cost of financing with remained earnings is 14 percent, and the before-tax cost of debt financing is 11 percent. As a student of FIN-3203, you are required to explain the role of the corporate tax rate on estimating WACC when the corporate tax rate i 30 percent and 45 percent.